How to detect server missing in dnode

gistfile1.js

// CLIENT 
var dnode = require('dnode');
var EventEmitter = require('events').EventEmitter;

var dnode = new dnode();

dnode.addListener('error', function(err){
    console.log('ERREUR  ' + err);
});

dnode.connect(5050, function (remote, conn) {
    setInterval(function () {
        console.log(remote); // Always show { zing: [Function] }, even after server has stop
        remote.zing(66, function (n) {
            console.log('n = ' + n);
        });
        }, 1000);
});

// SERVER
var dnode = require('dnode');

var server = dnode({
    zing : function (n, cb) { cb(n * 100) }
});

server.listen(5050);


// SCENARIO :
// 1. launch server
// 2. launch client
// 3. kill server